Biology - a science of exception, Biology


Some common examples to prove it are -

1.       Embryos of dicot plants have 2 cotyledons but in cuscuta (Dodder plant or amer bel or Akash bel) cotyledons are absent.

2.       Nucleus generally present in all cells except R.B.C. of mammals (in camel & lama present), sieve tubes of phloem of plants.

3.       DNA present in all animal viruses except influenza virus, polio virus, reo virus in which RNA present.

4.       RNA present in all plant viruses except cauliflower mosaic virus in which DNA present.

5.       In human 206 bones present, in human having 6 fingers in one hand 209 bones present.

6.       In birds urinnary bladder absent but present in ostrich.

7.       Kangaroo rat never drinks water in life.

8.       DNA is double strandded but in fx 174 bacteriophage single stranded DNA present.

9.       RNA is single strended but in wound tumour virus & reo virus it is double stranded. 

10.     Sexual reproduction usually occurs at puberty but in Ambyostoma's axolotal larva, it occurs at larval stage. This process is paedeogenesis and stage is neotany.

11.     Blood of all vertebrtes is red but in corcharinus (shark) it is colour less.

12.     Mammals are viviparous while Platypus, Echidna are oviparous & Kangroos or marsupials (having marsupium ponch) are ovo-viviparous.

13.     Fishes usually respire by gills but in Protopterus, Lepidosiren, Ceratodus lungs present (Dipnoi).

14.     Heart of all reptiles is incomplete 4 chambered but in crocodelia 4 chambered.

15.     In pisces heart is 2 chambered but in dipnoi 3 chambered.

16.     Mostly birds fly except ostrich, kiwi & penguine.

17.     Mammals do not fly except bat & lemur.

18.     Usually young ones are produced from zygotes while dron (male) of honey bee are formed from unfertilized egg by parthenogenesis. Dron is not having father but forefather (Nana) is present.

19.     Chromosomes number in diseased human may be 45 or 47.

20.     Femur is largest bone of human body while stapes is smallest bone.

Posted Date: 10/8/2012 4:22:14 AM | Location : United States

Related Discussions:- Biology - a science of exception, Assignment Help, Ask Question on Biology - a science of exception, Get Answer, Expert's Help, Biology - a science of exception Discussions

Write discussion on Biology - a science of exception
Your posts are moderated
Related Questions
Species diversity An important attribute of a community is its species diversity. The diversity is calculated both by the number of species (richness) and the relative abundanc

Find the initial osmotic pressure at room temperature of a cell if the only ions present are CaCl2 on either side of the membrane. Assume the concentrastions for K+ and Cl- from Ta

Process of Respiration Respiratory and Circulator System Gaseous exchange that is intake of oxygen and output of carbon dioxide, takes place at the respiratory surface since

De Vega Annuloplasty :  Classic De Vega annuloplasty is done using 2'0' double armed polyester suture with pledgets on either end. It starts with one of the needles passed fr

Q. What is the difference between cerebrum and brain? What are the major parts of these structures? The concept of brain or encephalon comprehends the cerebrum mostly referred

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

What is the difference between alpha glucose and beta glucose? Why are they different?

Ice age is an interval of geologic time between 2 million and 10,000 years ago during that period the northern hemisphere experienced several episodes of continental glacial advan

List the two primary targets to assess the good sugar control 1) There are two primary targets to assess the effectiveness of the management plan on glycemic (sugar) controls.